[SOLVED] Calculating required number of wins

Hi (Hi)

I'm making a spreadsheet which will calculate the number of wins required to achieve a given win ratio (expressed as a percentage.) My problem is when someone wins an additional round, they have also played one extra round (and this variance causes the required number of wins to change.)

The table looks something like this:

Wins: www

Rounds Played: xxx

Win%: yy%

Required Win%: zz%

Number of Wins Required: ??

My question is - What formula would I use to calculate the number of wins required?

(Headbang) This is quite frustrating since I know it can be done and I'm sure I've done it before, but I can't put my finger on it.